I have designed and built an inexpensive
VermiHarvester out of a five-gallon plastic pail, a plastic pipe, some scrap plywood and some 1/8" welded wire mesh hardware cloth. Some of these photos are of early attempts that finally led to the current design.
(Helpful Advice:
When you overlap the hardware cloth, be sure that the overlapping edges are on top. or the same side as the large filler hole. Overlaps on the bottom will fill with finely screened material and block the free passage of finished vermicompost)
You might need to click on the bottom left of this to see the slideshow.